• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.1-8
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• 2005

The industrial induction motor is widely used in the rotating electrical machine for the transmission of power. It is very reliable equipment, but it could lead to the loss of production and lift when failure occurs. Therefore, the failure data is acquired and analyzed by attaching an exclusive instrument to existing induction motor. However, these instruments could lead to side effects, increasing the production costs, because they are very expensive. The purpose of this study is the development of an induction motor bearing failure diagnosis system constructed using LabVIEW which can be supplied the kernelled function, process monitoring and current signature analysis. In addition, the availability and reasonability of the constructed system was examined for an induction motor with failure defects in outer raceway and ball bearing. From the results, it shows that failure diagnosis system constructed is useful for real-time monitoring with detection of bearing defects over the web.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.57-64
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• 2021

The domestic semiconductor industry can produce various products that will satisfy customer needs by diversifying assembly parts and increasing compatibility between them. It is necessary to improve the production line as a method to reduce the work-in-process inventory (WIP) in the assembly line, the idle time of the worker, and the idle time of the process. The improvement of the production line is to balance the capabilities of each process as a whole, and to determine the timing of product input or the order of the work process so that the time required between each process is balanced. The purpose of this study is to find the optimal WIP and buffer size through SA (Simulated Annealing) that minimizes lead time while matching the number of two parts in a parallel assembly line with bottleneck process. The WIP level and buffer size obtained by the SA algorithm were applied to the CONWIP and DBR systems, which are the existing production systems, and the simulation was performed by applying them to the new hybrid production system. Here, the Hybrid method is a combination of CONWIP and DBR methods, and it is a production system created by setting new rules. As a result of the Simulation, the result values were derived based on three criteria: lead time, production volume, and work-in-process inventory. Finally, the effect of the hybrid production method was verified through comparative analysis of the result values.

• Journal of the Society of Naval Architects of Korea
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• v.46 no.1
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• pp.78-86
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• 2009

A capacity calculation and process analysis is a very important part for the entire ship production planning. Ship's production plan is set up with a concept that the product is produced based on the capacity achievable by the processes while general manufacturing sets up the production plan based on product lead-time. Therefore, in case the calculation of capacity for each process of shipbuilding yard is different from actual conditions, a series of production plan - ship table composition, dual schedule plan and execution schedule plan, etc - may accumulate errors, lose reliability of planning information and cause heavy cost deficit in this course. In particular, in case of new shipbuilding yard, stocks between processes are built up and half blocks are not supplied in timely manner, and that is sometimes due to the clumsiness of the operator but it is more often because of the capacity to execute each process is not logically calculated. Therefore, this paper presents the process to calculate the assembly leadtime and assembly process capacity for shipbuilding yard assembly factory. This paper calculated the block type for calculation of assembly lead time based on block DAP(detailed assembly procedure), and introduced cases that calculate production capacities by assembly surface plate by considering the surface plate occupied area of the blocks that change depending on assembly field area and assembly processes through assembly simulation.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.1
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• pp.31-37
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• 2011

Recently gantry-type robot with 3 axes rectangular coordinates have been studied in the many industrial production equipment and machinery fields. To acquire a good handling and motion performance of this robot, reducing the settling-time and securing the accurate-transfer positioning under high-speed conditions should be required. However when robot is moved in high-speed, the large inertia of robot can lead to serious vibration of robot's head. The time-delayed control characteristics of this robot can also lead to tracking error. In this research, the analysis of the effects of higher order positional-profile is carried out to assure high-speed performance and stiffness specifications. To remove the residual vibration caused by kinematic coupling effect of dual-servo gantry, we develop a dual-servo gantry of rotary type that moving frame of x-axis rotates about z-axis. In order to decrease the tracking error, the 3 type lead-filter through system identification was applied respectively. From the experimental results, it was shown that zero-order series leader-filter has the best performance about tracking error and settling time.

• 보존과학연구
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• s.30
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• pp.137-147
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• 2009

Mireuk temple site is located in Iksan, on the North Jeolla province in Korea, and confirmed tiles, potteries, metals, glasses and other materials that are remaining between Baekje Kingdom and Joseon period after excavations. It is also detected that production and supply of the materials in this era were started inside the country(domestic) at that time. This is important information for the understanding of the production and circulation systems. In this study, lead isotope ratios of 18 samples includedlead glass, crucibles and glazed rafter tiles excavated from Mireuk Temple Site of Baekje era were analyzed for the provenance study of raw glass material supply and distribution of glass products. The results of lead isotope ratio analysis have shown that all raw materials were located in the distribution area of Baekje region and also confirmed to be accord with the previous research results. As comparing the lead isotope ratios of glass and glass materials excavated from Mireuk Temple Site with Miyajidake tomb from Fukuoka Prefecture in Japan, it is found that the same raw materials were used for glass production. It means that there is the active connection between Mireuk temple site and Miyajidake and that these areas are sharing the same materials at the same period. It also shown that artifacts excavated from Miyajidake were strongly influenced from Baekje culture. And it is estimated that there is a possibility of the use ofsame materials whether the supplies of them are from a specific place of Baekje or not

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.2
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• pp.117-129
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• 2005

This paper considers a make-to-order inventory-production system in which customer orders are admitted only when the number of outstanding customer orders is below a value committed by the system. We deal with general distributions for the customer order Inter-arrival, production, and replenishment lead time processes. Monotonicities of the optimal average cost with respect to these distribution parameters are established using sample path coupling arguments. When distributions are given as an exponential one, we implement a sensitivity analysis on the optimal inventory policy and show that it has monotonicities with respect to system costs using dynamic programming.

• Korean Journal of Heritage: History & Science
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• v.47 no.4
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• pp.48-57
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• 2014

More than 30 lead beads have been excavated from buddhist temples and sites but the production times are unknown the origin. The aim of this study is to estimate manufacturing technique and provenance of 11 beads through the chemical composition and isotope analysis. Results shows that the lead beads are composed of high-purity lead and cast using for 2 semicircle moulds. Furthermore, 11 lead beads are similar in size, chemical composition and casting methods. Lead isotope analysis data suggest that the provenance of lead beads are not Korea peninsula. Also it is estimated that 11 lead beads were divided in 2 groups considering the time and places of production. The future works will be executed additional scientific analysis and historical background due to confirm the manufacturing system and provenance.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.4
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• pp.109-116
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• 2015

This paper is concerned with the single vendor single buyer integrated production inventory problem. To make this problem more practical, space restriction and lead time proportional to lot size are considered. Since the space for the inventory is limited in most practical inventory system, the space restriction for the inventory of a vendor and a buyer is considered. As product's quantity to be manufactured by the vendor is increased, the lead time for the order is usually increased. Therefore, lead time for the product is proportional to the order quantity by the buyer. Demand is assumed to be stochastic and the continuous review inventory policy is used by the buyer. If the buyer places an order, then the vendor will start to manufacture products and the products will be transferred to the buyer with equal shipments many times. The mathematical formulation with space restriction for the inventory of a vendor and a buyer is suggested in this paper. This problem is constrained nonlinear integer programming problem. Order quantity, reorder points for the buyer, and the number of shipments are required to be determined. A Lagrangian relaxation approach, a popular solution method for constrained problem, is developed to find lower bound of this problem. Since a Lagrangian relaxation approach cannot guarantee the feasible solution, the solution method based on the Lagrangian relaxation approach is proposed to provide with a good feasible solution. Total costs by the proposed method are pretty close to those by the Lagrangian relaxation approach. Sensitivity analysis for space restriction for the vendor and the buyer is done to figure out the relationships between parameters.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.1 no.1
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• pp.37-44
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• 1978

The purpose of this study is to search for an efficient application method in solving delay-phenomenon problems which influence upon total production cost through case study. The method of this study is an experimental study based on cutting time data in lead cutting operations from "Lead Cutting Machine (Stripper)" and its service rate data from a large electronic products company which utilizes conveyor line system for the products "Car Stereo" The procedure of this experimental study is as follows; 1) Using loading(Man-Hour) analysis technique j,1 order to analyse and evaluate Production capacity, efficiency, operation and idle rate assembly charge, waiting and service cost -when its are controlled by stripper operator(server) 2) Establishing adequate waiting time model of finite population caused by the interference of 4 stripper machine which is drawn from mathematical statistics testing, that is, goodness of fit test in the waiting and service rate and to search for optimal solution by utilizing the above mentioned model The experimental result was that amount to 8,546,618won Per year was brought down, that is, by optimum point, it shows a decrease as compared with Present point. The major limitation of this experimental study is that the Queue in the Finite Population, so to speak. it comes from the interference of 4 stripper machine dealt with this case were limited only on the Car Stereo conveyor line. Further study of application of this application method to the areas such as material handling, personnel management marketing and transportation management is strong1y recommended.trong1y recommended.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1999.04a
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• pp.426-426
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• 1999

;There are many sources of uncertainty in a typical production and inventory system. There is uncertainty as to how many items customers will demand during the next day, week, month, or year. There is uncertainty about delivery times of the product. Uncertainty exacts a toll from management in a variety of ways. A spurt in a demand or a delay in production may lead to stockouts, with the potential for lost revenue and customer dissatisfaction. Firms typically hold inventory to provide protection against uncertainty. A cushion of inventory on hand allows management to face unexpected demands or delays in delivery with a reduced chance of incurring a stockout. The proposed strategies are used for the design of a probabilistic inventory system. In the traditional approach to the design of an inventory system, the goal is to find the best setting of various inventory control policy parameters such as the re-order level, review period, order quantity, etc. which would minimize the total inventory cost. The goals of the analysis need to be defined, so that robustness becomes an important design criterion. Moreover, one has to conceptualize and identify appropriate noise variables. There are two main goals for the inventory policy design. One is to minimize the average inventory cost and the stockouts. The other is to the variability for the average inventory cost and the stockouts The total average inventory cost is the sum of three components: the ordering cost, the holding cost, and the shortage costs. The shortage costs include the cost of the lost sales, cost of loss of goodwill, cost of customer dissatisfaction, etc. The noise factors for this design problem are identified to be: the mean demand rate and the mean lead time. Both the demand and the lead time are assumed to be normal random variables. Thus robustness for this inventory system is interpreted as insensitivity of the average inventory cost and the stockout to uncontrollable fluctuations in the mean demand rate and mean lead time. To make this inventory system for robustness, the concept of utility theory will be used. Utility theory is an analytical method for making a decision concerning an action to take, given a set of multiple criteria upon which the decision is to be based. Utility theory is appropriate for design having different scale such as demand rate and lead time since utility theory represents different scale across decision making attributes with zero to one ranks, higher preference modeled with a higher rank. Using utility theory, three design strategies, such as distance strategy, response strategy, and priority-based strategy. for the robust inventory system will be developed.loped.